Hydrofoil semisubmarine



Feb. 25, 1969 E URAM 3,429,287

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INVENTOR.

E Earl M. om if 3,429,287 HYDROFOIL SEMISUBMARINE Earl M. Uram, New London, Conn., assignor, by mesne assignments, to the United States of America as represented by the Secretary of the Navy Filed Jan. 16, 1967, Ser. No. 609,690 US. Cl. 114-665 18 Claims Int. Cl. B63b 1 28; B63g 8/04 ABSTRACT OF THE DISCLOSURE A shallow-running submersible is provided having an albacore-type main hull and incorporating a surfacepiercing dihedral hydrofoil system. Primary control is located in a control body suspended above the surface of the Water by the hydrofoils, the main hull being entirely immersed during normal operations. An air-breathing main propulsion plant may be used, air intake and exhaust being accomplished through passage in the hydrofoils. Dihedral foil flaps and a horizontal stern plane are operated at minimum angles with the horizontal stern plane positioned outside the boundary layer of the ship. Control cables extend through the hydrofoil system to the interim of the main hull. Counter-rotating propellers provide propulsive force.

This invention relates to hydrofoil-supported vessels and, more particularly, to such vessels having at least one hull body which remains submerged or substantially submerged when the vessel is underway.

In the search for hull configuration which may attain higher speeds than those attainable by conventional ships, the hydrofoil has evolved which at operating speeds physically lifts its attached hull body out of the water, thereby substantially reducing water resistance. Higher speeds result since existing hydrofoil craft are supported at operating speeds by their submerged low-resistance foil surfaces. There is a definite limit, however, to the speed and size of craft which may utilize these foil surfaces because of power plant requirements and the Weight which may be supported by hydrofoil surfaces.

Conventional hydrofoils thus are limited to relatively small craft and have not heretofore been applicable to ships having displacements on the order of 3,000 tons or more. It is desirable, nevertheless, that the speed and stability, among other salient features, of hydrofoils and hydrofoil-supported hulls be made available to heavier vessels, and it is to this end that the present invention is directed.

In effecting improvements in ships it has been the aim, in one line of endeavor, to increase the speed and enhance the operating characteristics of ships in the 3,000-ton displacement class, and particularly those ships in this class having air-breathing power plants. Surface-running hulls of heavier vessels have inherent limitations in wave resistance and drag which preclude significant speed increases beyond the 35-knot region. Thus, the search for higher performance hulls has been extended to submersibles and, in relation to this invention, to shallow-running submersibles.

Background of the invention It has been determined that the speed-attenuating characteristics in regular waves of shallow-running submers- States Patent 3,429,287 Patented Feb. 25, 1969 ibles of substantially 3,000 tons displacement are very good. Where such a submersible is provided with an Albacore-type hull, operation at Froude numbers in the vicinity of unity has been achieved. At Froude numbers in this range the wave resistance of submersibles, running shallow, is substantially attenuated and is no longer the major factor in the vessels horsepower requirements. Speed-attenuating characteristics of the shallow-running vessel may be further improved for submersibles having air-breathing power plants by replacing the customary snorkel with dihedral hydrofoil surfaces which accommodate ducting for intake and exhaust gases, among other uses.

Summary of the invention The present invention provides a novel, high-speed hydrofoil vessel structure that is semi-submersible and includes a major hull body which is disposed entirely under the surface of the water at operating speeds. The major hull body is connected to a non-submersible control body, preferably by a surface piercing dihedral hydrofoil or hydrofoils which also provide ducting for intake and exhaust gases. In addition, the dihedral hydrofoils add stability to the craft, giving it superior ship motion capabilities.

Accordingly, it is an object of the present invention to provide an improved hull structure for high-speed ships in the 3,000-ton or more displacement class.

It is another object of the present invention to provide an improved ship hull assembly and configuration utilizing hydrofoil surfaces which permit increased speeds and exhibit improved ship motions in rough seas while maintaining reasonable horsepower requirements.

It is a still further object of this invention to provide an improved ship hull assembly and configuration utilizing hydrofoil control surfaces which will operate at increased speeds and Froude numbers in the vicinity of unity for vessels having displacements on the order of 3,000 tons.

Other objects, advantages and novel features of the invention will become apparent from the following detailed description when considered in conjunction with the accompanying drawings in which like numerals represent like parts throughout and wherein:

Brief description of the drawings FIG. 1 is a schematic view showing one embodiment of the present invention in an operational environment;

FIG. 2 is a side elevation view partly in section showing some of the control means and compartmentation of the embodiment of FIG. 1;

FIG. 3 is a graph comparing curves of effective horsepower in calm water for the embodiment of FIG. 1, a destroyer, a large bulb ship and a semisubmerged ship (decks awash);

FIG. 4 is a grap comparing curves of effective horsepower in regular 1.01 waves of the embodiment of FIG. 1, a destroyer, a large bulb ship and a semisubmerged ship (decks awash); and

FIG. 5 is a graph comparing curves of effective horsepower in regular 2.0 Waves of the embodiment of FIG. 1, a destroyer, a large bulb ship and a semisubmerged ship (decks awash).

Referring to FIG. 1, a preferred embodiment, the semisubmarine 11, is shown including a submerged main hull body 12 connected to and partially controlled by a main hydrofoil system 13. This hydrofoil system, in turn, supports a control house 16 which, under usual circumstances, remains out of the water and contains remote controls for ship propulsion and operation. Hydrofoil system 13 may be positioned on hull body 12 either forward or aft of the hull center of gravity so that its center of pressure may be correspondingly located relative to the hull center of gravity. Propulsive force is provided by main engines, not shown, in hull body 12, these engines being any of several conventional marine types, such as diesel, diesel-electric, turbine, turbo-electric, etc., or unconventional marine types such as modified aircraft gas turbine, or developed gas generator with free turbine, etc., which may be controlled directly or by command communication from a ship control station, not shown, in control house 16.

In the side elevation view of FIG. 2, the present embodiment is shown in an attitude it would assume at normal operating speeds. Hydrofoil system 13 is attached to hull body 12 preferably adjoining a flat mounting surface 17 provided for-this purpose. The mounting surface is disposed in the vicinity of the hulls center of gravity, and an intermediate neck 18 secured to the hull in a conventional manner, such as welding, bolting, eto., not shown, forms a base from which a pair of dihedral hydrofoils 21 and 22 extend. The forward area of surface 17 may extend above the contour of hull 12 and form the overhead of a submerged viewing station 24 which is provided with viewing ports 25. Propulsive force for the semisubmarine may be supplied by the main engines, not shown, through a power transmission system, not shown, to a single propeller, not shown, pair of counter-propellers 27 and 28 shown in FIGS. 1 and 2 or a hydro-pump-jet system, not shown, at the stern. At the stern of the hull 12 yaw control is provided by a pivotable, vertical plane or rudder 30 on the upper side and a pivotable, vertical plane or rudder 31 secured aft of a downwardly extending strut 32. Pitch motion of the vessel is controlled through rotation of a horizontal plane or flap 35, the necessary mechanical linkages extending from hull 12 through strut 32 in a conventional manner, not shown.

Control house 16 is supported above the fluid environment by upper depending hydrofoils 38 and 39 which, in turn, are supported by and attached to lower dihedral hydrofoils 21 and 22 which extend upwardly from neck 18. A main ship control station, not shown, is disposed in control house 16 and is energized from a power source 40 which preferably is disposed in hull 12 and which also contains the necessary drive motors, selsyns and linkages, not shown, for controlling pivotable planes 31 and 35. Control signals are relayed from the main ship control station to local controls for the main engines as indicated at 44, for pivotable vertical planes 30 and 31 as indicated at 45 and pivotable horizontal plane 35 as indicated at 46. For cargo carrying purposes, hull 12 may be partitioned into main desk compartments as indicated at 47 and 2nd deck compartments as indicated at 48. Personnel accommodations preferably are provided in viewing station 24, although it will be understood that hull 12 may be compartmented primarily for personnel, or primarily for liquid cargo or for a combination of these uses or other uses.

Since the embodiment shown is arranged to accommodate an air-breathing power plant, dihedral hydrofoils 21 and 22 include passages which may be either integral with the hydrofoils as shown or separate from the hydrofoil interiors. In the case of an integral system, hydrofoils 21 and 22 preferably are divided longitudinally into a forward intake section 50 and an aft exhaust section 51. The passages preferably extend through the protruding portions 54 and 55 of hydrofoils 21 and 22 terminating at the open ends thereof. Hydrofoils 21 and 22 incorporate control flaps 56 and 57, respectively, and this hydrofoil flap system provides stability and control effects in pitch, yaw and roll. It will be appreciated that this system provides correcting moments in pitch, yaw and roll upon excursion of the vessel in any of these senses from a running equilibrium trim condition and the flaps 56 and 57 in conjunction with the stern planes 35 and 30 and 31 provide attitude control in pit-ch and roll in turning maneuvers.

Superimposed in FIGS. 3, 4 and 5 are performance curves for a conventional destroyer, a semisubmerged ship (decks awash), a large bulb ship and the present hydrofoil semisubmarine ship. FIG. 3 presents an effective horsepower comparison of the four types just mentioned, showing that up to substantially 25 knots the power required of the hydrofoil semisubmarine is greater than that of the other two ship types of comparable displacement. This condition exists because the semisubmarine experiences its maximum wave-making resistance in this speed range. Between substantially 25 knots and 45 knots the three unusual ship types outperform the conventional destroyer. From substantially 30 knots and above, the hydrofoil semisubmarine is considerably superior to the other types included in the comparison. FIGS. 4 and 5 present an effective horsepower comparison in regular waves. As in the calm water comparison, the hydrofoil semisubmarine exceeds the other types in performance at speeds from substantially 35 knots and above in following-sea conditions.

It has been determined experimentally that in 1.0L and in 2.0L waves, in the condition where ship speed exactly equals wave celerity in overtaking seas, the hydrofoil semisubmarine locks-in with the wave pattern or planes experiencing no pitch or heaving motions. In 2.0L waves, the hydrofoil semisubmarine in its critical region has a substantially higher pitch response to the wave system than any of the other three ship types. However, very little can be done to control or alleviate this situation in the three other ship types because of the very large longitudinal metacentric height inherent therein while the very small longitudinal metacentric height of the hydrofoil semisubmarine affords a great advantage in that a coordinated control system may be included for activating main foil flaps 56 and 57 and stern plane 35 automatically through a pitch-sensing device, such as a simple bubble level with an electronic pickup and output, producing considerable improvement in pitch response. Since the pitch frequency of the hydrofoil semisubmarine is believed to be quite low, coordinated control also may be achieved by manual adjustments of the control surfaces. As to heave response for 1.0L and 2.0L regular waves, the heave characteristics of the hydrofoil semisubmarine are very superior to those of any of the three ship types with which it has been compared. The ship design of the present invention, with a relatively small hydrofoil section exposed to the water surface, presents an extremely small water-plane area with the result that the natural frequency in pitch, relative to the excitation from the wave system, is very near zero or virtually that of a submarine. The heave characteristics, therefore, are dictated by the hydrodynamic forces resulting from the pitch variations of the ship, by the ships change in proximity to the free surface, [and by the effect of the wave system on vertical force and pitching moment induced upon the ship due to its proximity to the surface as forcing functions.

In summary, the hydrofoil semisubmarine is considerably superior to conventional destroyers and other ship types developed or investigated for the purpose of alleviating motions in seas and for horsepower requirements as well as ship response to wave systems at speeds above substantially 35 knots. The ship concept of the present invention permits, with an appropriately coordinated flap and plane control system, a much more effective control over the influences of its environment than does the conventional ship. The structural features pose no considerable or unusual problems since main hull body 12 need have watertight integrity for shallow depths only and the dihedral hydrofoils supporting gondola 16 and providing additional stability and control bear considerably less weight and force than those currently in use to support the entire weight of smaller vessels. Main hull body 12 normally wouldhave neutral buoyancy so that in the event it is separated from its hydrofoil system it readily could be brought to the surface and, if carrying personnel, maneuvered by manual control of auxiliary devices.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

I claim:

1. In a submersible vessel having a single flotation member, the combination with said member of hydrofoils attached to a single mount on and extending above said member, said hydrofoils during normal operating procedures being disposed at or near the surface of the medium in which the vessel is disposed, whereby the stability and maneuvering capability of the vessel are improved.

2. The device of claim 1 wherein said hydrofoils are disposed at a positive dihedral angle and extend above the surface of the medium.

3. The device of claim 1 [and further including control means for controlling said vessel, said control means disposed above the medium and supported by said hydrofoils.

4. The device of claim 3 wherein said control means includes gondola means having a control station therein, said gondola means adapted to house personnel for manning said control station.

5. The device of claim 2 and further including control means for controlling said vessel, said control means disposed above the medium and supported by said hydrofoils.

6. The device of claim 5 wherein said control means includes gondola means having a control station therein, said gondola means adapted to house personnel for manning said control station.

7. The device of claim 4 wherein:

said submersible vessel includes an air-breathing propulsion system; and

said hydrofoils provide for passage of intake and exhaust gases of said propulsion system. 8. The device of claim 7 wherein said hydrofoils include control flaps for improving the stability and maneuvering capabilities of said submersible vessel.

9. The device of claim 8 wherein said submersible vessel is provided with a rudder and a pivotable horizontal plane for effecting pitch and yaw motion of the vessel, said rudder and said horizontal plane controlled from said control station.

10. A submersible vessel having control means disposed externally of the medium in which the vessel is supported: said vessel having a hull which is normally operated entirely below the surface of its supporting medium;

frame means attached to said hull and said control means for disposing said control means without the supporting medium during normal operating procedures of said vessel;

said control means normally disposed vertically above said hull;

said frame means including at least two pairs of support means disposed at opposite dihedral angles with respect to the vertical positioning of said frame means over said hull;

said pairs of support means including lower and upper hydrofoils deployed transverse to the longitudinal axis of said hull; said lower hydrofoils disposed at a positive dihedral angle with respect to the relative positions of said hull and said control means;

said submersible vessel including an air-breathing propulsion system;

said lower hydrofoils providing for passage of intake and exhaust gases of said air-breathing propulsion system;

said hull having a rudder and a pivotable horizontal plane controlled at said control means for effecting pitch and yaw motion of the vessel;

said lower hydrofoil having control flaps operable at said control means for assisting in improving the stability and maneuvering capabilities of the vessel;

said control means including gondola means having a control station therein and adapted to house personnel for manning said control station;

said gondola means attached to and supported by said upper hydrofoils;

said hull including a viewing station along its upper surface for accommodating personnel and equipment for the purpose of viewing and recording scenes in the vessels environment; and

said hull having a supporting base mounted on its upper surface for attachment thereto of said frame means;

said base and at least said lower hydrofoils accommodating said intake and exhaust gas passages and electrical connections and mechanical linkages between said control station and the interior of said hull;

said upper hydrofoils accommodating at least said electrical connections and mechanical linkages,

said upper hydrofoils intercepting said lower hydrofoils intermediate the ends thereof so that the ends of said intake and exhaust gas passages are deployed outward of and above the area of intersection of said lower and upper hydrofoils.

11. A submersible vessel comprising:

a single flotation member which is entirely immersed and a control means therefor which is disposed externally of the medium in which the vessel is supported;

frame means attaching said flotation member to said control means for disposing said control means without the supporting medium during normal operating procedures of said vessel,

said control means normally disposed vertically above said flotation member; said frame means including at least two pairs of support members disposed at opposite dihedral angles with respect to the vertical positioning of said frame means over said flotation member; and

said pairs of support means including lower and upper hydrofoils deployed transverse to the longitudinal axis of said flotation member,

said lower hydrofoils disposed at a positive dihedral angle with respect to the relative positions of said flotation member and said control means. 12. The device of claim 11 wherein:

said submersible vessel includes an air-breathing pro- I pulsion system; and said frame means provide for passage of intake and exhaust gases of said propulsion system. 13. The device of claim 12 wherein said lower hydrofoils provide for passage of intake and exhaust gases.

14. The device of claim 13 wherein: said flotation member is provided with a rudder and a pivotable horizontal plane for effecting pitch and yaw motion of the vessel,

said rudder and said horizontal plane controlled at said control means. 15. The device of claim 14 wherein: said lower hydrofoils are provided with control flaps for assisting in improving the stability and maneuvering capabilities of said submersible vessel,

said control flaps operable at said control means.

7 i 8 16. The device of claim 15 wherein: References Cited said control means includes ondola means having a control station therein, a UNITED STATES PATENTS said gondola means adapted to house personnel for 1 976 045 10 1934 Tim-ens 4 5 5 manning said control station. 17. The device of claim 16 wherein said gondola 5 2493482 H1950 Fish 114-665 means is attached to and supported by said upper hydro- 3257982 6/1966 Meldrum 114-46 foils.

18. The device of claim 17 and further including a viewing station disposed along the upper surface of said 10 flotation member for accommodating personnel and equipment for the purpose of viewing and recording scenes in ANDREW FARRELL, Pr Examinerthe vessels environment.

FOREIGN PATENTS 637,302 3/1962 Italy. 

